1. Field of the Invention
The present invention relates to a power divider and a radio-frequency transceiver system, and more particularly, to a power divider and a radio-frequency transceiver system capable of effectively enhancing an array antenna gain, reducing an array antenna area, optimizing an antenna radiation pattern, reducing a reflection loss, and enhancing a side lobe suppression capability.
2. Description of the Prior Art
An array antenna is an antenna system consisting of a plurality of identical antennas arranged according to a certain rule, and is widely used in a radar system. The commonly-seen array antenna system is implemented by a manufacturing process of a printed circuit board, and antennas and a power divider are disposed in different layers of a substrate. In order to connect signals between different layers, a via hole is taken as a bridge. However, since transmission of the signals between the different layers only relies on the via hole, when a position of the via hole is changed due to a process variation or a process inaccuracy, frequency shift occurs and an overall system performance is reduced. Moreover, since an operating frequency of the radar system is mostly utilized in a microwave frequency band, as the operating frequency is getting higher, a distance passed through the via hole may be longer. When the distance is close to a quarter wavelength of the signals, an impedance matching issue would become more serious. As a result, the corresponding design becomes more complex and the antenna gain is reduced, leading to a shorter detecting distance and a narrower scanning angle.
Therefore, how to avoid the frequency shift and the degradation of antenna performance of the array antenna due to the process inaccuracy of wiring between different layers has become an industry target. Moreover, to further enhance the antenna gain, so as to enhance the detecting distance or reduce a required area, is also the industry target.